This invention relates, in general, to a gun and in particular to a gun which uses a telescoping or floating barrel as part of a propellant gas discharge design used to eliminate the gun's recoil.
The floating barrel gun design of U.S. Pat. No. 6,490,959 B2 offered certain advantages over state of the art gun technology. Conventional recoilless guns, using propellant gas discharge to neutralize recoil, were developed in England and Germany during World War II and were used as battlefield artillery weapons. These guns eliminated recoil by discharging propellant gas from nozzles located behind the breech block into the environment in high velocity gas streams as the projectile was accelerated through the barrel. The floating barrel design, by transferring and compressing, before expelling the gas, offered a greater degree of control over the propellant gas and the possibility of higher projectile velocities for a given barrel length. However, as with the preliminary floating barrel design, expelling gas at a high velocity in a rearward direction into the environment created a zone behind the gun which could be very hazardous to personnel nearby and precluded the use of the gun as a close-carry weapon. This specification deals with novel innovations in invention U.S. Pat. No. 6,490,959 B2 which makes possible a recoilless gun with a safer means of discharging the propellant gas used to counter the gun's recoil and may make possible a close-carry recoilless weapon, even a gas discharge operated recoilless handgun.
The previous invention described a prototype gun designed to include two barrels, an internal or floating barrel housing the projectile and an external barrel containing the propellant cartridge. When the porous propellant cartridge fired, part of the firing chamber gas was transferred to a chamber within the gun, which lay between the two concentric barrels, while both the projectile and floating barrel were accelerated forward. The chamber to which the propellant gas was diverted is created by an annulus or ring at the base of the floating barrel and flange at the front of the external barrel. The gas transfer was accomplished by transfer grooves in the wall of the external barrel which extended from adjacently above the base of the floating barrel into the firing chamber. When the floating barrel moved past the region where the grooves ended, the gas flow from the firing chamber terminated and the motion of the floating barrel compressed the gas which accumulated in the chamber. A semi-rigid piston was placed between the propellant charge and the floating barrel/projectile mass in order to increase the efficiency of the gas transfer by delaying the projectile's immediate acceleration until the piston ruptured.
By diverting propellant gas to a chamber within the gun, and then compressing this gas by the forward movement of the floating barrel, the kinetic energy of the moving barrel could be used to raise the pressure of the diverted gas. Raising the pressure of the diverted gas converted firing chamber energy into recoil-countering energy since the compressed gas was expelled through the body of the external barrel in a rearward direction into the environment, stopping the rearward motion of the entire gun. While the gas in the forward chamber was venting, the gas was held in a state of high compression and the floating barrel was prevented from moving rearward during the venting by a gasket which applied frictional force on the internal barrel to hold it in position within the external barrel. This ablative gasket was difficult to automatically manipulate in a mechanical way in repositioning the internal barrel for multiple firings.
The gun was also a prototype with a stationary breech block and had to be disassembled after each firing.
Further research with the basic gun design, determined that the design, if modified to expel the high pressure recoil countering gas within the interior of the gun itself, by positioning the passageway voids through the floating barrel annulus, might be used to produce a recoilless close-carry weapon. If the gas discharge is delayed until the projectile exits the weapon, and the gas is expelled from the forward chamber into the interior of the outer barrel of the gun at the same time or shortly after the breech block of the gun is unlocked from the receiver i.e. external barrel, as in short recoil operated semi-automatic handguns, the gas that is discharged is partially deflected off the unlocked breech block as the breech block is forced to move rearward. The pressure of the expanding gas in the external barrel creates an additional force which is on the base of the floating barrel and which forces the gun in a forward direction. With the external barrel acting as a divergent nozzle, the velocity of the discharged gas can be made to increase substantially and can be used to overcome the inefficiency of the venting process whereby some of the vented gas strikes the breech block and the rear areas of the gun producing a recoiling force.
An object of the present invention is to provide in the floating barrel delivery system an automatic mechanical mechanism for holding the internal and external barrels at the near maximum distance of relative movement within the gun during the firing cycle of the weapon, in order that the recoil-countering gas discharge occurs at a high pressure and, after the gas is discharged, automatically releasing both barrels at the completion of the firing cycle in order that the barrels may be repositioned to their pre-actuation position.
It is another object of this invention to provide in the floating barrel gun design an automatic mechanical mechanism of venting the recoil-countering gas accumulated in the forward chamber into the firing chamber after the projectile has left the gun and in this manner providing a gun which is safe and efficient in overcoming the recoil force.
A further object is to provide a description of how the aforementioned inventions when combined with state of the art ballistic technology can be used to produce a recoilless close-carry weapon.